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1/* linux/include/linux/clockchips.h
2 *
3 * This file contains the structure definitions for clockchips.
4 *
5 * If you are not a clockchip, or the time of day code, you should
6 * not be including this file!
7 */
8#ifndef _LINUX_CLOCKCHIPS_H
9#define _LINUX_CLOCKCHIPS_H
10
11#ifdef CONFIG_GENERIC_CLOCKEVENTS
12
13# include <linux/clocksource.h>
14# include <linux/cpumask.h>
15# include <linux/ktime.h>
16# include <linux/notifier.h>
17
18struct clock_event_device;
19struct module;
20
21/* Clock event mode commands for legacy ->set_mode(): OBSOLETE */
22enum clock_event_mode {
23 CLOCK_EVT_MODE_UNUSED,
24 CLOCK_EVT_MODE_SHUTDOWN,
25 CLOCK_EVT_MODE_PERIODIC,
26 CLOCK_EVT_MODE_ONESHOT,
27 CLOCK_EVT_MODE_RESUME,
28};
29
30/*
31 * Possible states of a clock event device.
32 *
33 * DETACHED: Device is not used by clockevents core. Initial state or can be
34 * reached from SHUTDOWN.
35 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.
36 * PERIODIC: Device is programmed to generate events periodically. Can be
37 * reached from DETACHED or SHUTDOWN.
38 * ONESHOT: Device is programmed to generate event only once. Can be reached
39 * from DETACHED or SHUTDOWN.
40 * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily
41 * stopped.
42 */
43enum clock_event_state {
44 CLOCK_EVT_STATE_DETACHED,
45 CLOCK_EVT_STATE_SHUTDOWN,
46 CLOCK_EVT_STATE_PERIODIC,
47 CLOCK_EVT_STATE_ONESHOT,
48 CLOCK_EVT_STATE_ONESHOT_STOPPED,
49};
50
51/*
52 * Clock event features
53 */
54# define CLOCK_EVT_FEAT_PERIODIC 0x000001
55# define CLOCK_EVT_FEAT_ONESHOT 0x000002
56# define CLOCK_EVT_FEAT_KTIME 0x000004
57
58/*
59 * x86(64) specific (mis)features:
60 *
61 * - Clockevent source stops in C3 State and needs broadcast support.
62 * - Local APIC timer is used as a dummy device.
63 */
64# define CLOCK_EVT_FEAT_C3STOP 0x000008
65# define CLOCK_EVT_FEAT_DUMMY 0x000010
66
67/*
68 * Core shall set the interrupt affinity dynamically in broadcast mode
69 */
70# define CLOCK_EVT_FEAT_DYNIRQ 0x000020
71# define CLOCK_EVT_FEAT_PERCPU 0x000040
72
73/*
74 * Clockevent device is based on a hrtimer for broadcast
75 */
76# define CLOCK_EVT_FEAT_HRTIMER 0x000080
77
78/**
79 * struct clock_event_device - clock event device descriptor
80 * @event_handler: Assigned by the framework to be called by the low
81 * level handler of the event source
82 * @set_next_event: set next event function using a clocksource delta
83 * @set_next_ktime: set next event function using a direct ktime value
84 * @next_event: local storage for the next event in oneshot mode
85 * @max_delta_ns: maximum delta value in ns
86 * @min_delta_ns: minimum delta value in ns
87 * @mult: nanosecond to cycles multiplier
88 * @shift: nanoseconds to cycles divisor (power of two)
89 * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE
90 * @state_use_accessors:current state of the device, assigned by the core code
91 * @features: features
92 * @retries: number of forced programming retries
93 * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME.
94 * @set_state_periodic: switch state to periodic, if !set_mode
95 * @set_state_oneshot: switch state to oneshot, if !set_mode
96 * @set_state_oneshot_stopped: switch state to oneshot_stopped, if !set_mode
97 * @set_state_shutdown: switch state to shutdown, if !set_mode
98 * @tick_resume: resume clkevt device, if !set_mode
99 * @broadcast: function to broadcast events
100 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
101 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
102 * @name: ptr to clock event name
103 * @rating: variable to rate clock event devices
104 * @irq: IRQ number (only for non CPU local devices)
105 * @bound_on: Bound on CPU
106 * @cpumask: cpumask to indicate for which CPUs this device works
107 * @list: list head for the management code
108 * @owner: module reference
109 */
110struct clock_event_device {
111 void (*event_handler)(struct clock_event_device *);
112 int (*set_next_event)(unsigned long evt, struct clock_event_device *);
113 int (*set_next_ktime)(ktime_t expires, struct clock_event_device *);
114 ktime_t next_event;
115 u64 max_delta_ns;
116 u64 min_delta_ns;
117 u32 mult;
118 u32 shift;
119 enum clock_event_mode mode;
120 enum clock_event_state state_use_accessors;
121 unsigned int features;
122 unsigned long retries;
123
124 /*
125 * State transition callback(s): Only one of the two groups should be
126 * defined:
127 * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME.
128 * - set_state_{shutdown|periodic|oneshot|oneshot_stopped}(), tick_resume().
129 */
130 void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *);
131 int (*set_state_periodic)(struct clock_event_device *);
132 int (*set_state_oneshot)(struct clock_event_device *);
133 int (*set_state_oneshot_stopped)(struct clock_event_device *);
134 int (*set_state_shutdown)(struct clock_event_device *);
135 int (*tick_resume)(struct clock_event_device *);
136
137 void (*broadcast)(const struct cpumask *mask);
138 void (*suspend)(struct clock_event_device *);
139 void (*resume)(struct clock_event_device *);
140 unsigned long min_delta_ticks;
141 unsigned long max_delta_ticks;
142
143 const char *name;
144 int rating;
145 int irq;
146 int bound_on;
147 const struct cpumask *cpumask;
148 struct list_head list;
149 struct module *owner;
150} ____cacheline_aligned;
151
152/* Helpers to verify state of a clockevent device */
153static inline bool clockevent_state_detached(struct clock_event_device *dev)
154{
155 return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED;
156}
157
158static inline bool clockevent_state_shutdown(struct clock_event_device *dev)
159{
160 return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN;
161}
162
163static inline bool clockevent_state_periodic(struct clock_event_device *dev)
164{
165 return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC;
166}
167
168static inline bool clockevent_state_oneshot(struct clock_event_device *dev)
169{
170 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT;
171}
172
173static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev)
174{
175 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED;
176}
177
178/*
179 * Calculate a multiplication factor for scaled math, which is used to convert
180 * nanoseconds based values to clock ticks:
181 *
182 * clock_ticks = (nanoseconds * factor) >> shift.
183 *
184 * div_sc is the rearranged equation to calculate a factor from a given clock
185 * ticks / nanoseconds ratio:
186 *
187 * factor = (clock_ticks << shift) / nanoseconds
188 */
189static inline unsigned long
190div_sc(unsigned long ticks, unsigned long nsec, int shift)
191{
192 u64 tmp = ((u64)ticks) << shift;
193
194 do_div(tmp, nsec);
195
196 return (unsigned long) tmp;
197}
198
199/* Clock event layer functions */
200extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt);
201extern void clockevents_register_device(struct clock_event_device *dev);
202extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
203
204extern void clockevents_config(struct clock_event_device *dev, u32 freq);
205extern void clockevents_config_and_register(struct clock_event_device *dev,
206 u32 freq, unsigned long min_delta,
207 unsigned long max_delta);
208
209extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
210
211static inline void
212clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
213{
214 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, minsec);
215}
216
217extern void clockevents_suspend(void);
218extern void clockevents_resume(void);
219
220# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
221# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
222extern void tick_broadcast(const struct cpumask *mask);
223# else
224# define tick_broadcast NULL
225# endif
226extern int tick_receive_broadcast(void);
227# endif
228
229# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
230extern void tick_setup_hrtimer_broadcast(void);
231extern int tick_check_broadcast_expired(void);
232# else
233static inline int tick_check_broadcast_expired(void) { return 0; }
234static inline void tick_setup_hrtimer_broadcast(void) { }
235# endif
236
237extern int clockevents_notify(unsigned long reason, void *arg);
238
239#else /* !CONFIG_GENERIC_CLOCKEVENTS: */
240
241static inline void clockevents_suspend(void) { }
242static inline void clockevents_resume(void) { }
243static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
244static inline int tick_check_broadcast_expired(void) { return 0; }
245static inline void tick_setup_hrtimer_broadcast(void) { }
246
247#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
248
249#endif /* _LINUX_CLOCKCHIPS_H */